Occurs in more than 100 countries throughout Africa, Asia, Latin America, and on certain Caribbean and Pacific Islands

3.2 billion inhabitants at risk

300 - 500 million clinical cases

~ 1 - 2 million per year

World Malaria Report, WHO 2005

Representative Distributions of the Four Recognized Species of Human Malaria Parasites in the World Today

Distribution of species (%) in following areas (total no. of cases)

Species

Sub-Saharan Africa

Asia (all)(863)

Central Americaand Caribbean(178,242)

South America (859,480)

West andCentral (858)

East andSouthern (297)

P. falciparum

88.2

78.8

4.2

12.9

29.2

P. vivax

1.2

9.8

95.6

87.1

70.6

P. malariae

2.2

3.0

0.0

0.0

0.2

P. ovale

8.4

8.4

0.2

0.0

0.0

Carter and Mendis, Clin Microbiol Rev 2002

Global Reach of Malaria

In today's interconnected world, no country is immune from the hazards of malaria

The problem of malaria is rising. There are more cases of malaria today than 30 years ago

Major factors attributed to rise in malaria transmission

Environmental

Human activities

Drug resistance in malaria parasites

Vector populations

Malaria Mortality: Summary Statistics at the Beginning and End of the 20th Century

Region

Year

Total no. of deaths from malaria

% of all deaths due to malaria

Europe and North America

1900

80,000

0.8

1997

20

0.0001

Caribbean, Central and South America

1900

42,000

2

1997

4,000

0.05

Asia, China and Western Pacific

1900

2,800,000

9

1997

65,000

0.1

Sub-Saharan Africa

1900

210,000

6

1997

990,000

9

World minus Sub-Saharan Africa

1900

2,900,000

8

1997

69,000

0.08

Total World

1900

3,132,000

1997

1,059,020

Total World Annual Deaths/10,000

1900

19.4

1997

1.84

Carter and Mendis, Clin Microbiol Rev 2002

Source: Tom Wellems, NIH

Projected Risk of Malaria Transmission in the year 2020 based on a global temperature increase of 2ºF and no human efforts to contain the spread of malaria. Source: Pim Martens (http://www.exploratorium.edu/climate/global-effects/data3.html)

Drug resistance to P. falciparum from studies in sentinel sites, up to 2004. World Malaria Report, WHO 2005

Incubation period: Time between infection to first appearance of blood form parasites (varies between species). P. vivax and P. ovale have dormant liver form stage causing relapse infection (months to a year or more)

Chronicity of infection: P. malariae can be present in a host for up to 40 years